Cooling means for engine cylinders



April 19, 1949 Filed Aug. 6, 1945 J. C. RIFLE, JR

COOLING MEANS FOR ENGINE CYLINDERS 2 Sheets-Sheet l five/2257 $17265 CJ? COOLING MEANS FOR ENGINE CYLINDERS Filed Aug. 6, 1945- 4 ,2Sheets-Sheet 2 Patented Apr. 19, 1949 COOLING MEANS FOR ENGINE CYLINDERSJames C. Riple, Jr., Milwaukee, Wis., assignor to Avco ManufacturingCorporation, a corporation of Delaware Application August 6, 1945,Serial No. 609,203

Claims.

The invention relates to air cooled combustion engines.

in air cooled engines in which the cylinders are arranged in rows orlines, it is desirable to maintain the cylinders in closely spacedrelation and to provide cooling-means which does not require an increaseof the interspacing between the cylinders. It is also desirable toadequately cool the cylinder-heads in which the combustion chambers areformed as well as the cylinder barrels.

One object of the invention is to provide bafiies which coact with thefins of different areas on the cylinder-barrels and cylinder-heads forefiicient heat transfer from the cylinder-heads which are subjected togreater heat than the cylinders.

- Another object of the invention is to provide improved baffles whichform ducts and fiues for efllciently cooling the cylinder-heads and thecylinder-barrels.

Other objects of the invention will appear from the detaileddescription.

The invention consists in the several features hereinafter set .forthand more particularly defined by claims at the conclusion hereof.

In the drawings:

Fig. 1 is a side elevation of a pair of cylinders and their bafllesviewed from the intake side for air and embodying the invention, partsbeing shown in section.

Fig. 2 is a perspective view of a pair of baffles for one cylinder.

Fig. 3 is a side elevation of a cylinder and its bafiles Viewed from theoutflow side for air.

Fig. 4 is a side elevation of a pair of bafiles provided with means forclamping them around a cylinder.

Fig. 5 is a section taken on line 5-5 of Fig. 1.

Fig. 6 is a section taken on line 66 of Fig. 1.

The invention is exemplified with a pair of cylinders, generallydesignated 10, of an internal combustion engine. The cylinders arearranged in line and it is to be understood that the invention isapplicable to engines with any desirable number of cylinders. Eachcylinder comprises a barrel II in which a piston operates and acylinder-head H on the end of the cylinder and in which the usualcombustion chamber is formed. The inlet and exhaust valves are mountedin the cylinder-head outwardly of the combustion chamber. A cap I6 issecured to the outer end of head I 4 and usually encloses thevalve-operating mechanism,'as well understood in the art. The barrel IIis provided. with continuously annular circumferential fins I! forconducting the heat from the barrel, and which are usually formed bycutting continuous grooves in its outer periphery and are relativelythin in cross-section. The head i4 is provided with circumferential fins[5, which are of non-symmetrical contour and are usually integrally castwith the head, and for efficiency are required to conduct more heat fromthe head produced by the combustion of fuel in the head adjacent thevalves.

The invention includes a pair of complemental bafiles, generallydesignated 20, and disposed on diametrically opposite sides of eachcylinder, and which are spaced apart to form an inlet passage a for air,and an outlet passage b. The baffles for each cylinder are separated andadapted to form, with the fins i2 on the barrel I l, transverse passagesfor directing air from the side at which air fiows to the cylinderaround the barrel to the outlet side, to form, with fins I5 on head [4,

transverse passages for directing air from the.

inlet side around head M to the outlet side, and ducts or fiues forconducting air from areas around the outside of the baffle-membersextending around the fins l2 on the barrel H, longitudinally of thecylinders to supplementally cool the fins I5 on the cylinder-head l4.The baffles for each cylinder are of similar construction, disposed onopposite sides thereof and their ends are spaced apart to form thelongitudinally extendin inlet-passage a for air at one side of thecylinder and a longitudinally extendin diametrically opposite passage bfor the outflow of air. These passages extend longitudinally of thecylinder for the flow of air toall portions to be cooled.

Each baffle comprises a substantially fiat sidewall 22 which is adaptedto fit between contiguous sides of a pair of in-line cylinders andextends substantially the length of the cylinderbarrel II and head I4.Each bafile also comprises an inner arcuate wall 25 which extendslongitudinally along the fins l2 on barrel H and around a side-portionof the cylinder-barrel and conforms to the outer periphery of fins l2,for directing air circumferentially between said fins from the inletpassage a to the outlet passage b between the bafiies. Each wall 25substantially contacts the fins l2 to direct the air between said fins.Each arcuate wall 25 terminates in a bead 26 at the inlet passage a andis joined at its opposite end at the outlet passage b to a vertical wall21.

The arcuate wardly from the side-wall 22 of the same baffle wall 25 ofeach baflie is spaced in-.

and a bottom-wall 29 extends between walls 22, and 21 to form atransverse duct 28 which has an open end at the side of the cylinder andat one side of the inlet passage a. Each duct 28 receives air from saidopen end and conducts it around the arcuate wall 25 to the end of theduct 28 at the side of the cylinder where the outlet passage b islocated. The end-wall 2i and sidewall 22 of each bafiie are extendedlongitudinally of the cylinder to a top-end wall 30 which extends acrossthe corner of said walls 22, 2'5 to form a flue 3! which receives airfrom duct 28. Topend wall 3!] extends between the fins IS on head 14,which are disposed at the outer end of the zone of said head, which issubjected to the greatest heat, to extend flue 3| for additional coolingof the portion of the head Hi which is subjected to the greatest heat.Air which flows through ducts 28 to fiues SI is confined longitudinallyby the corner formed by end-wall 2i" and side-wall 22 so it will flowinto the spaces between the fins E5 on head i l and escape therefromthrough the outlet passage 22. A, curved flange 32 on each end-wall 2?is designed to provide the proper exit passageway for the air emergingfrom the grooves between fins it, thereby providing for maximum air flowat a given pressure differential.

Each side-wall 22 is secured by a screw 23 to the outer end of thecylinder. If desired, tie bolts 35 between lugs 34 secured on walls 38of the baiiles may be used to secure baffles around the cylinder.

The operation is as follows: air flows through the inlet passage abetween the bafiies to fins E2 on barrel ii and then circumferentiallyaround opposite sides of the barrel on the inner side of arcuate walls25, through the grooves between said fins to the outlet passage bbetween the baffles. This air cools the barrel. Air also flows frominlet passage a between the side-walls 22 and cylinder-head Hi to finsIE on head it and around and between said fins to the outlet passage 1)between the bafiies. Streams of air also pass into the transverse ducts28 formed by arcuate walls 25, side-walls 22, bottom wall 29 andend-wall 2? into the fiues 3! which communicate with the fins IE on headIt and the grooves between said fins. The flues 3! extend longitudinallyof the fins it: on that portion of head I which is subjected to thegreatest heat from the combustion chambers in the cylinders andterminate at the outer-most fin on said portion of the head. The streamsof air passing into flues 3| flow through the spaces between fins 5 tothe outlet passage 1). In this manner, the ducts 28 and lines 3|supplement the cooling of the portion of head M which is subjected togreatest heat for efficient cooling. The flanges 32 provide for themaximum fiow of air air emerging from the fiues 3|.

The construction described results in high efficiency in the transfer ofheat units from head i i and barrel ii of the cylinder, is simple, andfully utilizes the interspace between adjacent cylinders so that it isnot necessary to provide an increase of space between the cylinders forthe accommodation of the baliies. The batlles are supported entirelyfrom the cylinders, and may be readily applied thereto.

The invention is not to be understood as limited to the detailsdescribed, since these may be modified within the scope of theappendedclaims without departing from the. spirit and scope of theinvention.

Having thus" described the invention, what I claim as new and desire tosecure by Letters Patent is:

1. Cooling means for an air-cooled engine having a cylinder including acylinder-barrel provided with a series of circumferential fins, and acylinder-head provided with a series of circumferential fins,comprising: a pair of diametrically opposite complemental bafiies havingbetween "rem longitudinal and diametrically opposite inlet and outflowpassages for air and extending longitudinally for the flow of airtransversely to and from both series of fins; each baffle including anouter side-wall extending longitudinally along the barrel and the head,an inner wall extending circumferentially around a portion of andlongitudinally along the barrel, for directing an inner stream of airfrom the inlet passage around the fins on the barrel to the outletpassage, the outer wall being spaced from the inner wall, for directlngair transversely around the inner wall from the inlet passage, and astructure adjacent the outlet passage forming a flue extendinglongitudinally along the cylinder head which opens to the air on theouter side of the inner wall and for conducting said last named air tofins on the head and thence to the outlet passage;

2. Coolin means for an air-cooled engine hava cylinder including acylinder-barrel provided with a series of circumferential fins, andacylinder-head provided with a series of circumferential fins,comprising: a pair of diametrically opposite complemental baiiles havingbetween them longitudinal and diametrically opposite inlet and outfiowpassages for air and extending longitudinally for the flow of airtransversely to and from both series of fins; each baille including anouter side-wall extending longitudinallyalong the barrel and the head,an arcuate inner wall extending circumferentially around a portion ofand longitudinally along the barrel, for directing an inner stream ofair from the inlet passage, around the fins on the barrel to the outletpassage, the outer wall being spaced from the inner wall, for directingair transversely around the.

inner wall from the inlet passage, and a structure adjacent the outletpassage forming a flue extending, longitudinally along the cylinderhead, which opens to the air on the outer side of the inner wall and forconducting said last named air to fins on the head and thence to theoutlet assage.

3. Cooling means for an air-cooled engine having a cylinder including acylinder-barrel provided with a series of circumferential fins, and acylinder-head provided with a series of circumferential fins,comprising: a pair of diametrically. opposite complemental baflieshaving between.

them longitudinal and diametrically oppositeinlet and outflow passagesfor air and extending longitudinally for the flow of air transversely"to and from both series of fins; each baffle including a substantiallystraight outer side-wall extending longitudinally along the'barrel andthe head; an arcuate inner wall extending circumferentially-* around aportion of and longitudinally along the. barrel, for directing an innerstream of 'air'from: the inlet passage, around the'fins on thebarrelt'o: the outlet passage, the outer wall being spaced from theinner wall for directing air transversely around the inner wall from theinlet passage, and a structure adjacent the outlet passage forming-e;-flue extending longitudinally along the cylinder" head, which opens tothe air on the-'outer-si'de-off the inner'wall, and for conducting airtosaid' last named fins on the head and thence to the outlet passage.

4. Cooling means for an air-cooled engine havin a cylinder including acylinder-barrel provided with a series of circumferential fins, and acylinder-head provided with a series of circumferential fins,comprising: a pair of diametrically opposite complemental baflles havingbetween them longitudinal and diametrically opposite inlet and outflowpassages for air and extending longitudinally for the flow of airtransversely to and from both series of fins; each bafile including anouter side-wall extending longitudinally along the barrel and the head,an inner wall extending circumferentially around a portion of andlongitudinally along the barrel, for directing an inner stream of airfrom the inlet passage around the fins on the barrel to the outletpassage, the outer wall being spaced from the inner wall for directingair transversely around the inner wall from the inlet passage to theoutlet passage, and a structure adjacent the outlet passage at onecorner 01 the cylinder, forming a flue extending longitudinally alongthe cylinder head, which opens to the air on the outer side of the innerwall, and for conducting air to said last named air fins on the head andthence to the outlet passage.

5. Cooling means for an air-cooled engine having a cylinder, including acylinder barrel provided with a series of circumferential fins, and acylinder head provided with a series of circumferential fins of greaterdiameter than the fins on the barrel, comprising: a pair ofdiametrically opposite complemental baflles having between themlongitudinal and diametrically opposite inlet and outflow passages forair extending for the flow of air transversely to and from both seriesof fins; each bafile including an outer side-wall extendinglongitudinally along the barrel and the head, an inner wall extendingcircumferentially around a portion of and longitudinally along thebarrel, for directing an inner stream of air from the inlet passagearound the fins on the barrel to the outlet passage, the outer wallbeing spaced from the inner wall for directing air transversely aroundthe inner wall from the inlet passage, the inner wall extending to theinner fin on the head, for separating the air flowing around the fins onthe barrel from the air on the outer side of the inner wall, and astructure adjacent the outlet passage, forming a flue extendinglongitudinally of the cylinder head, which opens to the air on the outerside of the inner Wall, for conducting ale to fins on the head andthence to the outlet passage.

JAMES C. RIPLE, J R.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

